Learning. Exam 2 Results. Learning. Learning. Definition. Learning. Chapter 8. How Do We Learn? Operant Conditioning. Classical Conditioning

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1 Exam 2 Results Top Score: 49 Mean: Bimodal: 34 and 37 Median: 36 Standard Deviation: 5.81 To calculate your approximate grade, divide 49 by your score. Example: 36/49 = 73.5% = C Chapter How Do We Learn? Classical Pavlov s Experiments Extending Pavlov s Understanding Pavlov s Legacy Operant Skinner s Experiments Extending Skinner s Understanding Skinner s Legacy Contrasting Classical & Operant 3 4 by Observation Bandura s Experiments Applications of Observational Definition is a relatively permanent change in an organism s behavior due to experience. is more flexible in comparison to the genetically-programmed behaviors of Chinooks, for example

2 Stimulus-Stimulus How Do We Learn? to associate one stimulus with another. We learn by association. Our minds naturally connect events that occur in sequence years ago, Aristotle suggested this law of association. Then 200 years ago Locke and Hume reiterated this law. 7 8 Stimulus-Stimulus Response-Consequence to associate one stimulus with another. to associate a response with a consequence Classical to associate a response with a consequence. Ideas of classical conditioning originate from old philosophical theories. However, it was the Russian physiologist Ivan Pavlov who elucidated classical conditioning. His work provided a basis for later behaviorists like John Watson and B. F. Skinner. 11 Sovfoto Response-Consequence Ivan Pavlov ( ) 12 2

3 Pavlov s Experiments Before conditioning, food (Unconditioned Stimulus, US) produces salivation (Unconditioned Response, UR). However, the tone (neutral stimulus) does not. Pavlov s Experiments During conditioning, the neutral stimulus (tone) and the US (food) are paired, resulting in salivation (UR). After conditioning, the neutral stimulus (now Conditioned Stimulus, CS) elicits salivation (now Conditioned Response, CR) Acquisition Acquisition is the initial stage in classical conditioning in which an association between a neutral stimulus and an unconditioned stimulus takes place. Acquisition The CS needs to come half a second before the US for acquisition to occur. In most cases, for conditioning to occur, the neutral stimulus needs to come before the unconditioned stimulus. The time in between the two stimuli should be about half a second Extinction When the US (food) does not follow the CS (tone), CR (salivation) begins to decrease and eventually causes extinction. Spontaneous Recovery After a rest period, an extinguished CR (salivation) spontaneously recovers, but if the CS (tone) persists alone, the CR becomes extinct again

4 Stimulus Generalization Tendency to respond to stimuli similar to the CS is called generalization. Pavlov conditioned the dog s salivation (CR) by using miniature vibrators (CS) on the thigh. When he subsequently stimulated other parts of the dog s body, salivation dropped. Stimulus Discrimination Discrimination is the learned ability to distinguish between a conditioned stimulus and other stimuli that do not signal an unconditioned stimulus Extending Pavlov s Understanding Pavlov and Watson considered consciousness, or mind, unfit for the scientific study of psychology. However, they underestimated the importance of cognitive processes and biological constraints. Cognitive Processes Early behaviorists believed that learned behaviors of various animals could be reduced to mindless mechanisms. However, later behaviorists suggested that animals learn the predictability of a stimulus, meaning they learn expectancy or awareness of a stimulus (Rescorla, 1988) Biological Predispositions Biological Predispositions Pavlov and Watson believed that laws of learning were similar for all animals. Therefore, a pigeon and a person do not differ in their learning. However, behaviorists later suggested that learning is constrained by an animal s biology. Garcia showed that the duration between the CS and the US may be long (hours), but yet result in conditioning. A biologically adaptive CS (taste) led to conditioning and not to others (light or sound). John Garcia Courtesy of John Garcia

5 Biological Predispositions Pavlov s Legacy Even humans can develop classically to conditioned nausea. Pavlov s greatest contribution to psychology is isolating elementary behaviors from more complex ones through objective scientific procedures. Ivan Pavlov ( ) Applications of Classical Two Famous John Watson Quotes Watson used classical conditioning procedures to develop advertising campaigns for a number of organizations, including Maxwell House, making the coffee break an American custom. See also, Little Albert experiment John Broadus Watson 27 Brown Brothers Psychology as the behaviorist views it is a purely objective experimental branch of natural science. Its theoretical goal is the prediction and control of behavior. Introspection forms no essential part of its methods, nor is the scientific value of its data dependent upon the readiness with which they lend themselves to interpretation in terms of consciousness. The behaviorist, in his efforts to get a unitary scheme of animal response, recognizes no dividing line between man and brute. The behavior of man, with all of its refinement and complexity, forms only a part of the behaviorist's total scheme of investigation. Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select -- doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors. I am going beyond my facts and I admit it, but so have the advocates of the contrary and they have been doing it for many thousands of years. (1930) 28 Applications of Classical Alcoholics may be conditioned (aversively) by reversing their positive-associations with alcohol. Through classical conditioning, a drug (plus its taste) that affects the immune response may cause the taste of the drug to invoke the immune response. Operant & Classical 1. Classical conditioning forms associations between stimuli (CS and US). Operant conditioning, on the other hand, forms an association between behaviors and the resulting events

6 Skinner s Experiments Operant & Classical Skinner s experiments extend Thorndike s thinking, especially his law of effect. This law states that rewarded behavior is likely to occur again. Classical conditioning involves respondent behavior that occurs as an automatic response to a certain stimulus. Operant conditioning involves operant behavior, a behavior that operates on the environment, producing rewarding or punishing stimuli. Yale University Library 31 Operant Chamber Using Thorndike's law of effect as a starting point, Skinner developed the Operant chamber, or the Skinner box, to study operant conditioning. Walter Dawn/ Photo Researchers, Inc. From The Essentials of and, 3rd Edition by Michael P. Domjan, Used with permission by Thomson, Wadsworth Division Operant Chamber 32 The operant chamber, or Skinner box, comes with a bar or key that an animal manipulates to obtain a reinforcer like food or water. The bar or key is connected to devices that record the animal s response Shaping Types of Reinforcers Shaping is the operant conditioning procedure in which reinforcers guide behavior towards the desired target behavior through successive approximations. Any event that strengthens the behavior it follows. A heat lamp positively reinforces a meerkat s behavior in the cold. Reuters/ Corbis Fred Bavendam/ Peter Arnold, Inc. Khamis Ramadhan/ Panapress/ Getty Images A rat shaped to sniff mines. A manatee shaped to discriminate objects of different shapes, colors and sizes

7 Primary & Secondary Reinforcers Immediate & Delayed Reinforcers Primary Reinforcer: An innately reinforcing stimulus like food or drink. Immediate Reinforcer: A reinforcer that occurs instantly after a behavior. A rat gets a food pellet for a bar press. Conditioned Reinforcer: A learned reinforcer that gets its reinforcing power through association with the primary reinforcer. Delayed Reinforcer: A reinforcer that is delayed in time for a certain behavior. A paycheck that comes at the end of a week. 37 We may be inclined to engage in small immediate reinforcers (watching TV) rather than large delayed reinforcers (getting an A in a course) which require consistent study. 38 Reinforcement Schedules Ratio Schedules 1. Continuous Reinforcement: Reinforces the desired response each time it occurs. 2. Partial Reinforcement: Reinforces a response only part of the time. Though this results in slower acquisition in the beginning, it shows greater resistance to extinction later on. Fixed-ratio schedule: Reinforces a response only after a specified number of responses. e.g., piecework pay. Variable-ratio schedule: Reinforces a response after an unpredictable number of responses. This is hard to extinguish because of the unpredictability. (e.g., behaviors like gambling, fishing.) Interval Schedules Fixed-interval schedule: Reinforces a response only after a specified time has elapsed. (e.g., preparing for an exam only when the exam draws close.) Schedules of Reinforcement Variable-interval schedule: Reinforces a response at unpredictable time intervals, which produces slow, steady responses. (e.g., pop quiz.)

8 Punishment An aversive event that decreases the behavior it follows. 43 Punishment Although there may be some justification for occasional punishment (Larzelaere & Baumrind, 2002), it usually leads to negative effects. 1. Results in unwanted fears. 2. Conveys no information to the organism. 3. Justifies pain to others. 4. Causes unwanted behaviors to reappear in its absence. 5. Causes aggression towards the agent. 6. Causes one unwanted behavior to appear in place of another. 44 Extending Skinner s Understanding Skinner believed in inner thought processes and biological underpinnings, but many psychologists criticize him for discounting them. Cognition & Operant Evidence of cognitive processes during operant learning comes from rats during a maze exploration in which they navigate the maze without an obvious reward. Rats seem to develop cognitive maps, or mental representations, of the layout of the maze (environment) Latent Such cognitive maps are based on latent learning, which becomes apparent when an incentive is given (Tolman & Honzik, 1930). Intrinsic Motivation: The desire to perform a behavior for its own sake. Motivation Extrinsic Motivation: The desire to perform a behavior due to promised rewards or threats of punishments

9 Biological Predisposition Skinner s Legacy Biological constraints predispose organisms to learn associations that are naturally adaptive. Breland and Breland (1961) showed that animals drift towards their biologically predisposed instinctive behaviors. Marian Breland Bailey 49 Photo: Bob Bailey Skinner argued that behaviors were shaped by external influences instead of inner thoughts and feelings. Critics argued that Skinner dehumanized people by neglecting their free will. Falk/ Photo Researchers, Inc. 50 Applications of Operant Skinner introduced the concept of teaching machines that shape learning in small steps and provide reinforcements for correct rewards. Applications of Operant Reinforcement principles can enhance athletic performance. LWA-JDL/ Corbis In School 51 In Sports 52 Applications of Operant Reinforcers affect productivity. Many companies now allow employees to share profits and participate in company ownership. Applications of Operant In children, reinforcing good behavior increases the occurrence of these behaviors. Ignoring unwanted behavior decreases their occurrence. At work

10 by Observation Operant vs. Classical Herb Terrace Higher animals, especially humans, learn through observing and imitating others Imitation Onset Reprinted with permission from the American Association for the Advancement of Science, Subiaul et al., Science 305: (2004) 2004 AAAS. Neuroscientists discovered mirror neurons in the brains of animals and humans that are active during observational learning. by observation begins early in life. This 14-month-old child imitates the adult on TV in pulling a toy apart Applications of Observational Bandura's Experiments Unfortunately, Bandura s studies show that antisocial models (family, neighborhood or TV) may have antisocial effects. Courtesy of Albert Bandura, Stanford University Bandura's Bobo doll study (1961) indicated that individuals (children) learn through imitating others who receive rewards and punishments. Meltzoff, A.N. (1998). Imitation of televised models by infants. Child Development, Photos Courtesy of A.N. Meltzoff and M. Hanuk. Mirror Neurons Herb Terrace The monkey on the right imitates the monkey on the left in touching the pictures in a certain order to obtain a reward

11 Positive Observational Fortunately, prosocial (positive, helpful) models may have prosocial effects. Bob Daemmrich/ The Image Works 61 Television and Observational Gentile et al., (2004) shows that children in elementary school who are exposed to violent television, videos, and video games express increased aggression. Ron Chapple/ Taxi/ Getty Images 62 Modeling Violence Research shows that viewing media violence leads to an increased expression of aggression. Bob Daemmrich/ The Image Works Children modeling after pro wrestlers Glassman/ The Image Works 63 11